微分脉冲溶出伏安法结合化学计量学测定醚类除草剂

在pH=6.82的Britton-Robinson缓冲溶液中,采用循环伏安法和微分脉冲溶出伏安法对醚类除草剂甲羧除草醚(Bifenox)和三氟羧草醚(Acifluofen)的伏安行为进行了研究,发现吸附时间为50 s时此电化学体系达到平衡,而且微分脉冲溶出伏安法能给出较高的灵敏度,甲羧除草醚和三氟羧草醚分别在-685 mV和-700 mV处具有良好还原峰,但由于峰电位接近而谱峰重叠,很难分别测定.本文采用化学计量学方法来解析重叠峰并完成这两种除草剂的定量分析.甲羧除草醚和三氟羧草醚的测定线性范围分别为0.02～0.18 μg·5mL~(-1)和0.02～0.16 μg·5mL~(-1),检出限分别为0.0073 μg·5mL~(-1)和0.0068 μg·5mL~(-1).利用该方法对水样中的甲羧除草醚和三氟羧草醚进行直接测定,获得了较好的定量分析结果.     

Simultaneous Voltammetric Determination of Three Herbicides in Food and Water Samples with the Aid of Chemometrics

Differential pulse stripping voltammetry method(DPSV) was applied to the determination of three herbicides,ametryn,cyanatryn,and dimethametryn.It was found that their voltammograms overlapped strongly,and it is difficult to determine these compounds individually from their mixtures.With the aid of chemometrics,classical least squares(CLS),principal component regression(PCR) and partial least squares(PLS),voltammogram resolution and quantitative analysis of the synthetic mixtures of the three compounds were successfully performed.The proposed method was also applied to the analysis of some real samples with satisfactory results.     

微分脉冲阴极吸附溶出伏安法测定利多卡因

用微分脉冲阴极吸附溶出伏安法测定了利多卡因针剂的含量。浓度与波高的线性范围为1×10~(-7)～3×10~(-4)mol/dm~3。最低检测限l×10~(-8)mol/dm~3。回收率98.07±0.05%。     

差分脉冲溶出伏安法测定陶瓷器皿中铅和镉的溶出率

采用4%的乙酸浸泡陶瓷样品24 h,应用同位镀汞差分脉冲溶出伏安法测定了陶瓷样品中微量重金属铅、镉的溶出量。以0.1 mol/L的硝酸溶液做底液,0.1 mol/L的KCl溶液做支持电解质,2 g/L的Hg2+溶液做镀汞液,测得铅的溶出峰电位为-0.5 V(vsSCE),镉的溶出峰电位为-0.7 V(vsSCE),两者含量在5×10-4～1 mg/L和5×10-4～0.5 mg/L范围内峰电流和其含量呈良好的线性关系,检出限分别为2×10-4和4.3×10-3mg/L。     

微分脉冲阳极溶出伏安法测定碘离子

基于I-能被氧化生成IO₃^-的特性,以铂球电极为工作电极,研究了微分脉冲阳极溶出伏安法(DPAS)测定碘离子.由于产物IO₃^-在电极上有吸附,因而在+1.3V电清洗120s.在pH=4的0.1mol/LKH₂PO₄-K₂HPO₄缓冲溶液底液中,能检测出5.00×10^-7mol/L的I-,在5.00×10^-71.50×10^-5mol/L范围内I^-的浓度与峰电流有良好的线性关系.该方法用于海带、食用碘盐中碘的测定,取得了较好的结果.     

Electrolysis at the Interface between Two Immiscible Electrolyte Solutions: Determination of Acetylcholine by Differential Pulse Stripping Voltammetry

Abstract

A three-electrode system with the hanging electrolyte drop electrode (HEDE) was developed for the analytical exploitation of electrolysis at the interface between two immiscible electrolyte solutions (ITIES). The use of the differential pulse stripping voltammetry (DPSV) for the quantitative determination of the species which participates in a charge transfer reaction at ITIES was demonstrated with acetylcholine cation transfer across the water/nitrobenzene interface. Trace concentration of acetylcholine in water in the part per million level (ppm) can be determined. It was concluded that the electrolysis at ITIES represents the perspective method of chemical analysis.     

微分脉冲溶出伏安-偏最小二乘法同时测定代森锌和代森锰

采用循环伏安法讨论了两种常用的杀菌剂代森锰和代森锌在汞电极上的电化学还原反应机理,发现它们均具有良好的的伏安还原峰.采用微分脉冲溶出伏安法研究本体系时,获得的代森锰和代森锌的线性范围分别为0.005～0.07 mg/L和0.02～0.24 mg/L;检出限分别为4.10和12.8μg/L.由于这两种杀菌剂的分子结构很相似,它们的伏安波谱峰重叠严重,采用常规方法很难对它们分别进行测定.为解决波谱重叠的问题,本研究采用主成分回归和偏最小二乘法对波谱进行解析.结果表明,偏最小二乘法能得到较好的定量结果.利用本方法对几种蔬菜和水果样品进行分析,三氯甲烷作萃取剂的萃取率最大,回收率在95.5％～103％之间.     

微分脉冲溶出伏安法测定2,4-二硝基-1-萘酚

以Britton-Robinson(pH=8.0)缓冲液为底液,富集电位为-0.05V,富集时间为30s,电位扫描速率20mV/s,产生2个完全分离的峰,在-0.58±0.01V(vs.Ag/AgCl)处产生的峰灵敏度高且峰形好,故以此峰为定量峰。2,4_二硝基_1_萘酚浓度在6.00×10-8～2.00×10-6mol/L时与峰电流呈良好的线性关系,线性相关系数为0.9996。检出限为4.00×10-9mol/L,信噪比S/N约为10。     

Adsorptive Stripping Differential Pulse Voltammetry for Determination of Trace Amounts of Noscapine in Human Plasma

A new adsorptive anodic differential pulse stripping voltammetry method for the direct determination of noscapine at trace levels in human plasma of addicts is proposed. The procedure involves an adsorptive accumulation of noscapine on a hanging mercury drop electrode (HMDE), followed by oxidation of adsorbed noscapine by voltammetry scan using differential pulse modulation. The optimum conditions for the analysis of noscapine are pH = 8.5 using Britton‐Robinson (B‐R) buffer, accumulation potential of ?100 mV (vs. Ag/AgCl), and accumulation time of 150 s. The peak current is proportional to the concentration of noscapine, and a linear calibration graph is obtained at 0.015–2.75 μg mL^?1. A relative standard deviation of 1.28% (n = 5) was obtained, and the limit of detection was 7 ng mL^?1. The capability of the method for the analysis of real samples was evaluated by determination of noscapine in spiked human plasma and addicts, human plasma with satisfactory results.     

A Rapid Determination of Trace Amounts of Bismuth in Urine and Blood Using Differential Pulse Anodic Stripping Voltammetry at the Hanging Mercury Electrode

Abstract

Bismuth in 5 ml of blood or 10 ml of urine is determined by dilution to 100 ml with 0.25 M HCl, separation by anion exchange chromatography (Amberlite IRA-400 (Cl)), and measurement by differential pulse anodic stripping voltammetry in the presence of 0.1 M KCl.     

头孢噻肟钠降解产物在银微电极上示差脉冲阴极溶出伏安法的测定

基于包噻肟钠（ＣＴＸ）在０．１０ｍｏｌ／Ｌ ＮａＯＨ溶液中水浴降解产物含有巯基（－ＳＨ），在ＰＨ４．５ＮａＡｃ－ＨＡｃ介质中，于奶微电极上产生－灵敏的吸附伏安还原峰，峰电位Ｅｐ＝－０．５５Ｖ（ｖｓ．ＳＣＥ）。示差脉冲溶出峰电流与ＣＴＸ浓度在１．０＊１０＾－７－１．０＊１０＾－５ｍｏｌ／Ｌ范围内呈线性关系，方法可应用于模拟样品ＣＴＸ的检测，令人满意。     

Determination of Cobalt Ions in Natural Waters Using Differential Pulse Adsorptive Stripping Voltammetry

Abstract

Differential pulse adsorptive stripping voltammetry using dimethylglyoxime complexes in the presence of triethanolamine and ammonium chloride can be applied to the determination of cobalt (II) ions in natural waters with high sensitivity. The limit of detection is about 3 ppt. Actual analysis of estuary water are reported. In this particular case of natural water, the factors influencing the use of differential pulse adsorptive stripping voltammetry for the determination of cobalt are described in detail.     

微分脉冲吸附溶出伏安法测定苯胺的研究

苯胺经重氮化、偶合反应定量生成的偶氮化合物具有很强的电活性。作者用微分脉冲吸附溶出伏安法测定偶氮化合物来定量分析苯胺的含量。以ＮＨ３·Ｈ２Ｏ－ＮＨ４Ｃｌ（ｐＨ＝１０）缓冲液为底液，富集电位为－０１５Ｖ，富集时间１２０ｓ，电位扫描速度４ｍＶ／ｓ，在－０６７０Ｖ处产生一个灵敏度高、峰形好的溶出峰。苯胺浓度在１０－９～１０－７ｍｏｌ／Ｌ时与峰电流成线性关系。用印染厂土壤、废水和广州垃圾填埋场的渗出液作标准回收试验，平均回收率分别为９８２％、９７０％、９７５％，测定的相对标准偏差为４３％、４０％、３３％。     

流通电解池-连续介质交换差示脉冲阳极溶出伏安法同时测定镉、铟

本文采用自制流通电解池,在盐酸溶液中富集Cd(Ⅱ),In(Ⅲ),经连续介质交换,在选定的乙二胺-氯化钠溶液中进行差示脉冲阳极溶出。得到的镉、铟溶出峰△Ep≥100mV。波形完好。从根本上解决了盐酸溶液中Cd(Ⅱ)、In(Ⅲ)的阳极溶出峰相重叠的问题。建立了一个灵敏、快速,同时测定镉、铟的分析方法。     

银微盘电极上碘离子的示差脉冲溶出伏安法

基于Ｉ能与Ａｇ生成难溶出化合物特性，在银微盘电极上研究了Ｉ的示差脉冲溶出伏安法（ＤＰＳＶ）。该法不需镀汞，不要搅拌，可在较稀稀的支持电解质溶液中实施。于０．０８ｍｏｌ／ＬＨＡｃ－ＮａＣ及０．０１ｍｏｌ／ＬＥＤＴＡ介质中，能检出１．００×１０＾－８ｍｏｌ／Ｌ的Ｉ，Ｉ的浓度为５．００×１０＾－６－－１．２０×１０＾－８ｍｏｌ／Ｌ范围与峰电流有良好的线性关系。该法用于自来水中Ｉ的测定，相对偏差为４．３％     

铜膜差分脉冲阳极溶出伏安法测定药物中铋的含量

研究了铜膜电极代替汞膜电极测定重金属铋的差分脉冲溶出伏安法。实验了同位镀膜法测定铋的条件。在最佳实验条件下,Bi3+浓度在5×10-8~2×10-5mol/L范围内,其溶出峰峰高与浓度呈线性关系,检出限达到1×10-8mol/L。测定了一些药物中铋的含量,结果准确。     

微分脉冲溶出伏安法测定除草通

提出了苹果、土豆、西红柿中除草通残留量的电分析化学测定方法,研究了除草通在汞电极上的电化学行为,探讨了其电极反应机理。结果表明,除草通在汞电极上具有吸附性质,其电极反应为不可逆的还原过程。本方法的测量线性范围为0．01～0．16mg/L,检出限为9．1μg/L.     

芦丁的差示脉冲伏安法测定

研究了芦丁在pH 3.0的磷酸盐缓冲液中,在玻碳电极的吸附伏安行为.结果表明芦丁在本试验条件下存在一个准可逆的双电子双质子转移过程.建立了用差示脉冲伏安法测定芦丁含量的方法.在4.6×10-7~1.8×10-6mol/L范围内,芦丁的氧化峰电流与其浓度呈良好的线性关系,检出限为5.0×10-8mol/L.利用本法测定了槐花中芦丁的含量,效果良好.     

Oligonucleotide Functionalized Microporous Gold Electrode for the Selective and Sensitive Determination of Mercury by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV)

Abstract

A novel electrode modified with oligonucleotide and microporous gold was fabricated for the determination of mercury by differential pulse adsorptive stripping voltammetry (DPAdSV). Microporous gold was synthesized by electrochemical reduction using dynamic hydrogen bubble template. The oligonucleotide was immobilized on microporous gold by self-assembly. The prepared electrode exhibited an improved electrochemical response for mercury(II) ion because of the large surface area and excellent electron transfer capacity provided by microporous gold and the specific coordination between mercury ion and thymine bases in oligonucleotides. Under the optimal experiment conditions, the oligonucleotide functionalized microporous gold electrode had a linear relationship between the stripping current and mercury ion concentration in the range from 0.5 to 30?µg/L with a detection limit of 0.021?µg/L. Moreover, the prepared electrode exhibited good selectivity, reproducibility, repeatability and stability. Furthermore, the prepared electrode was applied to detect mercury in tap water with satisfactory results.